Field
Exemplary embodiments relate to a touch sensing unit, a touch screen panel having the touch sensing unit, and a method of driving the touch screen panel.
Discussion of the Background
Display devices are required for computer monitors, televisions, mobile phones, and the like, which are currently in wide use. The display devices for displaying images by using digital data include a cathode ray tube display device, a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting display, and the like. As the display devices become higher in resolution and larger in area, the transmission amount of data increases, and the transmission speed of data increases.
A touch screen panel is an input device that allows a user's instruction to be input by selecting an instruction content displayed on a screen of an image display device or the like with a user's hand or object.
To this end, the touch screen panel is formed on a front face of the image display device to convert, into an electrical signal, a contact position at which the user's hand or object is in direct contacted with the touch screen panel. Accordingly, the instruction content selected at the contact position is inputted as an input signal to the image display device. Such a touch screen panel can replace a separate input device, such as a keyboard or a mouse, connected to an image display device, and hence, its application fields have been gradually extended.
There are various methods of implementing touch screen panels, including a resistive layer method, an optical sensing method, and an electrostatic capacitance method. In the electrostatic capacitance method, multi-touch recognition can be implemented through a self-capacitance method and a mutual capacitance method. This utilizes a principle such that, when a pointer such as a person's finger is contacted with a surface of a touch screen panel, a position of the contact is recognized by detecting a change in the capacitance formed in a sensing cell (node) located on the contact surface, which is caused by the electric field of a human body.
The electrostatic capacitance method has higher durability and definition than the resistive layer method, and can carry out multi-touch recognition and proximity-touch recognition. Thus, the electrostatic capacitance method can be utilized in a wide range of various applications. For example, in the electrostatic capacitance method, a touch may be sensed by applying a touch driving signal to transmitter pads (Tx pads) coupled to transmitter lines (Tx lines), and then sensing a charge amount generated by a change in voltage of receiver pads (Rx pads) connected to receiver lines (Rx lines) by using mutual capacitance formed between the Rx pads and the Tx pads.
However, a touch reaction may be generated by coupling between Rx pads within a touch position and lines of Tx pads corresponding thereto. That is, a position other than an actual touch position may be erroneously recognized as the touch position, and therefore, accuracy in recognizing a touch position may be reduced as a result of a ghost phenomenon.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.